strange bahavior of ArcSinh
- To: mathgroup at smc.vnet.net
- Subject: [mg110927] strange bahavior of ArcSinh
- From: mathfanda <KKratky at seznam.cz>
- Date: Mon, 12 Jul 2010 01:04:10 -0400 (EDT)
Dear Mathematica users,
I have found a strange behavior of ArcSinh.
Without ArcSinh this makes a nice graph as expected.
With ArcSinh I get a strange warning in Mathematica 7.0.
Is it a bug or a feature?
Mathematica 5.2 gives no warnings.
Best regards
Pavel
Mathematica 7.0 for Linux x86 (64-bit)
Copyright 1988-2009 Wolfram Research, Inc.
In[1]:= !!test.m
f[b_]:=(
j={{0,1},{-(2b Cos[2t]),0}};
s=NDSolve[{m'[t]==j.m[t],m[0]==IdentityMatrix[2]},m,{t,0,2Pi}]//
First;
Tr[m[2Pi]/.s]
);
p1:=Plot [ f[b],{b,-1,1}];
p2:=Plot [ ArcSinh[f[b]],{b,-1,1}];
In[1]:= <<test.m
In[2]:= p1
Out[2]= -Graphics-
In[3]:= p2
ReplaceAll::reps:
{m'[t] == {{0, 1}, {1.99992 Cos[2 t], 0}} . m[t], m[0] == {{1, 0},
{0, 1}}}
is neither a list of replacement rules nor a valid dispatch
table, and so
cannot be used for replacing.
ReplaceAll::reps:
{m'[t] == {{0., 1.}, {1.99992 Cos[2. t], 0.}} . m[t],
m[0.] == {{1., 0.}, {0., 1.}}} is neither a list of replacement
rules nor
a valid dispatch table, and so cannot be used for replacing.
ReplaceAll::reps:
{m'[t] == {{0, 1}, {1.91829 Cos[2 t], 0}} . m[t], m[0] == {{1, 0},
{0, 1}}}
is neither a list of replacement rules nor a valid dispatch
table, and so
cannot be used for replacing.
General::stop: Further output of ReplaceAll::reps
will be suppressed during this calculation.
Plot::exclul: {Re[Tr[m[2 Pi] /.
{m'[t] == {{0, 1}, {-2 b Cos[2 t], 0}} . m[t],
m[0] == {{1, 0}, {0, 1}}}]] - 0} must be a list of
equalities or
real-valued functions.
Out[3]= -Graphics-